<strong>OBJECTIVE:</strong> To investigate the respiratory health effects of living near roadways.<p></p> <p><strong>METHODS:</strong> We administered a questionnaire to Windsor school children. Exposure to roadways was defined as the total length of roadways within a 200 meter radius around the postal code of each household calculated using geographic information systems.</p> <p><strong>RESULTS:</strong> The adjusted odds ratios comparing the highest to the lowest exposure (roadway density) quintiles, were statistically significant for wheeze 1.23 (95% CI: 1.07 to 1.41) (P = 0.0041) and wheeze with dyspnea 1.27 (95% CI: 1.05 to 1.52) (P = 0.0125). Expressed as a continuous variable roadway density was associated with asthma, odds ratio 1.08 (95% CI: 1.012 to 1.149) equivalent to an 8% relative increase in the odds of asthma for an interquartile increase (0.6 km) in roadway density.</p> <p><strong>CONCLUSIONS:</strong> Residential traffic appears to adversely influence respiratory health.</p>